The present invention relates to a linear motor, a driving system thereof and a manufacturing method thereof, or in particular a linear motor comprising an armature wound with a coil having two magnetic poles, upper and lower, with alternate magnetic pole teeth in opposed relation to each other, and a control method thereof.
The prior art such as JP-A-63-310361 discloses a linear pulse motor of such a structure that the lead wire processing is simplified to reduce the manufacturing cost. In the structure of such a linear motor, a two-phase pulse rotational motor is expanded linearly.
In the conventional linear motor, the leakage of the magnetic fluxes passing through the gap between the magnetic pole teeth of the magnetic pole plate and the two magnetic poles of the armature is generally so large that the propulsive force of the motor is small as compared with the excitation current. Further, in view of the fact that the magnetic attractive force acts unidirectionally between the armature and the mover, a large burden is imposed on the mover support mechanism, thereby leading to the problem of a distorted structure.
The object of the present invention is to provide a linear motor and a method of manufacturing thereof, in which the magnetic flux leakage is reduced thereby to reduce the magnetic attraction force between the armature and the mover.
According to one aspect of the invention, there is provided a linear motor comprising a first member and a second member, wherein the first member includes at least a magnetic pole of a first magnetic polarity having a first opposed portion and a magnetic pole of a second magnetic polarity having a second opposed portion, and the second member is held by the first opposed portion and relatively moved by being held by the second opposed portion. The first member is made of an iron core and a winding, and the second member is made of a permanent magnet, a magnetic material or a single type of winding or a combination of a plurality of materials.
According to another aspect of the invention, there is provided a method of manufacturing a linear motor, comprising the steps of producing by segmenting the iron core of the first member vertically or horizontally with respect to the direction of relative movement of the first member and the second member and combining the segmented portions of the first member thereby to produce a magnetic pole of a first magnetic polarity having a first opposed portion and a magnetic pole of a second magnetic polarity having a second opposed portion.